From bhardy@helix.nih.gov Tue Jul 12 01:52:35 1994 Received: from helix.nih.gov for bhardy@helix.nih.gov by www.ccl.net (8.6.9/930601.1506) id AAA12775; Tue, 12 Jul 1994 00:55:04 -0400 Received: by helix.nih.gov (931110.SGI/1.35(big_sgi-1.0)) id AA23398; Tue, 12 Jul 94 00:56:00 -0400 Date: Tue, 12 Jul 94 00:56:00 -0400 From: bhardy@helix.nih.gov (Barry J. Hardy) Message-Id: <9407120456.AA23398@helix.nih.gov> To: chemistry@ccl.net Subject: Response to request for learning programs CCLers, I enclose below my original post for 1) interest in a particular learning program MCMD1D and 2) gathering a list of learning programs. As one might see from the summary of responses I failed to gather a good set of responses to 2) in terms of actual programs. I did receive the sugestions though of where to look (osc, QCPE, basic textbooks, etc.). The job remains to be done though (he says as he heads off on a trip tomorrow, :) ). Perhaps the recent suggestion by Herbert Homeier is relevant here. We need a Guide to Available Chemistry Software (GACS) Project. Also, my experiences agree quite well with Robert Topper's comments. Getting back to 2), I would summarize the situation for finding/using comp chem programs as teaching tools: a) Work with books such as: Allen & Tildesley & its programs Warren Hehre & its programs Numerical Recipes & its routines Lipkowitz & Boyd b) Scour QCPE, osc, archie, gopher sites etc.; i.e. dig around [How many CCLers out here recently got no 'work' done one evening because of reading their email, browsing in loops around the Web or searching through endless hierarchical gopher site menus; :)] c) Standard Packages, Dig around for scripts On 1) I have decided to make the program available directly on a testing basis and later through QCPE, osc and anon ftp. Enjoying the Net connection, Barry J. Hardy ********************************** ORIGINAL POST 1) I developed a relatively simple program MCMD1D for a recently published paper (B.J. Hardy & R.W. Pastor, J. Comp. Chem., 15, 208 (1994)); simulations using the program are described in the Appendix.). The program allows one to study the application of Monte Carlo and Molecular Dynamics algorithms to simple one dimensional functions. I am currently musing on the program's fate. (The program is not robust software neither does it have any fancy graphics interface.) My question to CCLers is thus: "Is there any interest in using the program as a learning/teaching tool and if so what are your requirements to make this useful?". 2) What programs are out there that cover the basics of computational chemistry techniques? I volunteer to summarize a list of programs back to CCL based on contributors' suggestions. A brief description of its distribution/availability, price if commercial, method(s) covered, references etc. could be included with the program suggestion. ********************************** SUMMARY OF REPLIES RELATED TO 2) Don't overlook the tutorials that come with most of the major commercial packages. I hear that Biosym's is particularly good and I know that Tripos is working on updataing some of theirs. There is also the book from Hehre, et al. on quantum mechanical methods-- this is a self-study guide that has gotten rave reviews. Yvonne Martin Abbott Laboratories MartinY@Abbott.com ******* From lipkowitz@chem.iupui.edu Thu Jun 30 09:31:55 1994 Barry, welcome to the world of science. I don't have a need for the home-made program you describe because I implement full-blown modeling packages complete with graphics in my courses (organic chemistry) for teaching purposes. I suspect people who teach stat. mech. may be inclined to use your stuff. The second question concerning modeling programs can be found in the Appendix of a review series I've been editing with Don Boyd called "Reviews in Computational Chemistry" published by VCH Inc. New York. Each volume has a complete listing of programs, what they do and whom to contact for more info. Good luck, Kenny. ************************ QCPE (Quantum Chemistry Program Exchange) is a repository for programs of this sort. Dr. Richard Counts at Indiana University runs it; I'm pretty sure the address has been given on CCL in the past. (Sorry, but I don't have it here right now). Irene Newhouse ************************ Dear Barry, Why not donate your code to the Ohio State software archive? That way, people can evaluate it more directly and be able to provide an answer to your question "Is there any interest in using the program as a learning/teaching tool and if so what are your requirements to make this useful?". (especially the last part). I am developing an advance p chem course for our chemical engineering seniors to take this fall as an elective, and I plan to focus on the use of computational methods. One of the assignments I have developed is for the students to write their own Metropolis MC code to calculate and for a 1D Lennard-Jones potential. I feel that by doing this they will gain a better understanding of the technical issues involved in MC calculations than by using BOSS or some other "monster" code right away. But I wasn't planning to have them develop an MD code...so as the next assignment, I could have them do some calcs using your code to compare MC to MD (for 1D problems). I will have to look at your J. Comp. Chem. article to see what your own conclusions are, but (as one of very few people who has coded up, run, and compared MC and MD algorithms for various properties) my own conclusion has been that MC is the method of choice for computing thermodynamic (equilibrium) properties (i.e., it converges more rapidly w.r.t. the statistical error for a fixed number of samples and equilibrates more rapidly)....but MD allows one to compute time-dependent properties of the system which of course cannot be obtained through MC. I'd be interested to hear your perspective, since you have obviously started from scratch and therefore are less likely to be predjudiced by "conventional wisdom" on this point. Best wishes and good luck in your research, Robert Topper ************************************************************************ Prof. Robert Q. Topper internet: topper@cooper.edu Department of Chemistry phone: (212) 353-4378 The Cooper Union FAX: (212) 353-4341 Cooper Square subway: take the N/R to 8th/NYU New York, NY 10003 USA or the 6 to Astor Place The Cooper Union for the Advancement of Science and Art, established by Peter Cooper in 1859, is a private institution of higher learning where all students receive full-tuition scholarships. ************************************************************************ From SB@CHEM.UNI.WROC.PL Tue Jul 12 08:52:42 1994 Received: from sun1000.ci.pwr.wroc.pl for SB@CHEM.UNI.WROC.PL by www.ccl.net (8.6.9/930601.1506) id HAA15434; Tue, 12 Jul 1994 07:54:44 -0400 Received: from hera.math.uni.wroc.pl by sun1000.ci.pwr.wroc.pl (5.0/SMI-SVR4) id AA16055; Tue, 12 Jul 1994 13:53:17 --100 Received: from chem.uni.wroc.pl (ichuwr.chem.uni.wroc.pl) by hera.math.uni.wroc.pl (5.0/SMI-SVR4) id AA04607; Tue, 12 Jul 1994 13:53:00 --100 Received: from ICHUWR/SMTPQueue by chem.uni.wroc.pl (Mercury 1.11); Tue, 12 Jul 94 13:56:37 +0100 Received: from Mailqueue by ICHUWR (Mercury 1.11); Tue, 12 Jul 94 13:56:00 +0100 From: "Slawomir Berski" To: chemistry@ccl.net Date: Tue, 12 Jul 1994 13:55:57 GMT+1 Subject: PM3,AM1 - radicals Priority: normal X-Mailer: Pegasus Mail v3.1 (R1) Message-Id: Content-Length: 228 Hi, I'm interested in comparison of experimental and calculated by PM3 and AM1 methods heats of formation of different radicals. Do you know any references on this topic ? Thanks ! Slawek From DAREK@ichn.ch.pwr.wroc.pl Tue Jul 12 08:54:56 1994 Received: from sun1000.ci.pwr.wroc.pl for DAREK@ichn.ch.pwr.wroc.pl by www.ccl.net (8.6.9/930601.1506) id IAA15691; Tue, 12 Jul 1994 08:12:30 -0400 Received: from ichn.ch.pwr.wroc.pl by sun1000.ci.pwr.wroc.pl (5.0/SMI-SVR4) id AA16533; Tue, 12 Jul 1994 14:10:52 --100 Received: from ICHN_1/MAILQUEUE by ichn.ch.pwr.wroc.pl (Mercury 1.11); Tue, 12 Jul 94 14:14:23 +100 Received: from MAILQUEUE by ICHN_1 (Mercury 1.11); Tue, 12 Jul 94 14:13:56 +100 From: "Dariusz C.Bienko" Organization: Inst. of Inorg. Chem. PWr. To: chemistry@ccl.net Date: Tue, 12 Jul 1994 14:13:51 GMT+100 Subject: guestion about program Priority: normal X-Mailer: Pegasus Mail v3.1 (R1a) Message-Id: <26E6F7005C@ichn.ch.pwr.wroc.pl> content-length: 252 Czesc, I search for the program to count the potential energy distribution from Gaussian 92(90) output. I'd like it to count the percentage contribution of internal coordinate in the normal mode. Darek From suter@physik.unizh.ch Tue Jul 12 09:53:10 1994 Received: from milliways.physik.unizh.ch for suter@physik.unizh.ch by www.ccl.net (8.6.9/930601.1506) id JAA16525; Tue, 12 Jul 1994 09:05:09 -0400 Received: by milliways.physik.unizh.ch (5.0cf2.19) id AA09273; Tue, 12 Jul 94 15:06:01 +0200 From: Hans-Ueli Suter Message-Id: <9407121306.AA09273@milliways.physik.unizh.ch> Subject: AO based DFT codes To: chemistry@ccl.net Date: Tue, 12 Jul 1994 15:05:58 +0200 (MET DST) Cc: suter@ccl.net (Hans-Ueli Suter) X-Mailer: ELM [version 2.4 PL22] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 732 Dear Netters, I would be very happy to hear something about the current use and the experiences of some AO based desity functional codes. As far as I see this includes the programs DMol (Delley), G92/DFT (Pople), DeFT and DeMon and ADF. For these there are the following two questions: (i) Is this list complete, which program should be addeed? (ii) What program are you using, what is your experience with it. how fast, how userfriendly and how stable is your program? I will try to summarize the answers and submit them to the net, if requested. sorry, for wasting your time, Hans Ulrich Suter CSCS, Manno, Switzerland. From gene@jersey.cray.com Tue Jul 12 13:52:49 1994 Received: from cray.com for gene@jersey.cray.com by www.ccl.net (8.6.9/930601.1506) id MAA21158; Tue, 12 Jul 1994 12:54:45 -0400 Received: from jersey.cray.com by cray.com (Bob mailer 1.3) id AA04808; Tue, 12 Jul 94 11:55:19 CDT Received: by jersey.cray.com id AA21741; 5.0/CRI-5.6; Tue, 12 Jul 94 12:54:58 EDT Date: Tue, 12 Jul 94 12:54:58 EDT From: gene@jersey.cray.com (Eugene Fleischmann) Message-Id: <9407121654.AA21741@jersey.cray.com> To: suter@physik.unizh.ch Cc: chemistry@ccl.net, gene@jersey.cray.com, george@gravity.cray.com, raeuchle@gravity.cray.com Subject: Re: CCL:AO based DFT codes Content-Length: 3622 > From chemistry-request@ccl.net Tue Jul 12 12:04 EDT 1994 > Subject: CCL:AO based DFT codes > To: chemistry@ccl.net > Cc: suter@ccl.net (Hans-Ueli Suter) > > Dear Netters, > > I would be very happy to hear something about the current > use and the experiences of some AO based desity functional > codes. As far as I see this includes the programs > DMol (Delley), G92/DFT (Pople), DeFT and DeMon and > ADF. For these there are the following two questions: > > (i) Is this list complete, which program should be addeed? > > (ii) What program are you using, what is your experience > with it. how fast, how userfriendly and how stable > is your program? > > I will try to summarize the answers and submit them to the > net, if requested. > > sorry, for wasting your time, > > Hans Ulrich Suter > CSCS, Manno, Switzerland. > Greetings, Prof. Suter. With regard to your inquiry: > (i) Is this list complete, which program should be addeed? The only addition to your list is: DGauss, from Cray Research, Inc. > (ii) What program are you using, what is your experience > with it. how fast, how user-friendly and how stable > is your program? I use DGauss regularly, for obvious reasons. It is a VERY user-friendly DFT program as a stand-alone code, and even MORE user-friendly when used with the GUI for Silicon Graphics known as: UniChem. DGauss is VERY fast on Cray vector hardware, and it is also fast on SGI workstations. The program uses gaussian functions, in the spirit of standard "ab initio" programs today, to build the density and solve the Kohn-Sham equations. In its present implementation, DGauss uses an all-electron non-relativistic Hamiltonian. The major functions of DGauss include geometry optimizations for stationary points (minima and saddle points) on a potential energy hypersurface. These optimizations are carried out using analytical first derivatives. Until the next release, vibrational frequencies as well as infrared intensities are computed with finite difference techniques. For fixed or optimized geometries, DGauss evaluates molecular properties such as Mulliken charges, multipole moments, molecular orbitals, electron densities, spin densities, and electrostatic potentials. At present, SCF calculations can be carried out on the local spin density (LSD) functional level, or at the non-local (NLSD) level using Becke-Perdew or Becke-Stoll-Preuss-Pavlidou gradient corrections after the SCF or Becke-Perdew or Becke-Lee-Yang-Parr corrections self-consistently. DGauss calculates molecular orbitals (MOs) and the corresponding orbital energies. It is designed to take full advantage of the current knowledge of vector and parallel algorithms in the evaluation of integrals and other computationally demanding numerical procedures, such as the calculation of the exchange-correlation terms which are calculated numerically on a finite grid. For more information about DGauss and/or UniChem please send mail to any of the following individuals at Cray Research, Inc: Dr. George Fitzgerald george@gravity.cray.com Dr. Thomas Raeuchle raeuchle@gravity.cray.com Dr. Eugene Fleischmann gene@jersey.cray.com Best Wishes, Gene ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Eugene D. Fleischmann, Ph.D. Computational Chemist Cray Research, Inc. (609) 252-1250 121 Commons Way gene@jersey.cray.com Princeton, NJ 08540 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ From kevin@chem.ucla.edu Tue Jul 12 14:52:51 1994 Received: from uclachem.chem.ucla.edu for kevin@chem.ucla.edu by www.ccl.net (8.6.9/930601.1506) id OAA22804; Tue, 12 Jul 1994 14:12:18 -0400 Received: from houksg1.chem.ucla.edu by uclachem.chem.ucla.edu (Sendmail 5.61/1.05) id AA23355; Tue, 12 Jul 94 11:09:41 -0700 Received: by houksg1.chem.ucla.edu (911016.SGI/911001.SGI) for @uclachem.chem.ucla.edu:chemistry@ccl.net id AA25956; Tue, 12 Jul 94 11:13:02 -0700 Date: Tue, 12 Jul 94 11:13:02 -0700 From: kevin@chem.ucla.edu (Kevin Condroski) Message-Id: <9407121813.AA25956@houksg1.chem.ucla.edu> To: chemistry@ccl.net Subject: Basis Sets for Trasition Metals (Mn) Fellow theoreticians: I am pursuing an ab initio study of Mn complexes, and I have learned the hard way that small basis sets (i.e., STO-3G*, and Hehre's 3-21G extension for transition metals) are woefully inadequate for such calculations due to convergence difficulties and downright inaccurate results (to put it bluntly). I have found several references to more extensive basis sets from the literature; however, most of these are atomic sets without polarization functions included that have been optimized for molecular calculations. Again, these are quite inaccurate without polarization functions. If anyone has any leads to a collection of basis sets that are optimized for molecular calculations (online or otherwise), I would greatly appreciate your input. Any suggestions for polarization functions to add to the better atomic basis sets are also welcome. Thanks for your help! Kevin Condroski (PostDoc, UCLA) kevin@houksg1.chem.ucla.edu From billg@SCGROUP.BARRNET.NET Tue Jul 12 15:00:00 1994 Received: from mail.barrnet.net for billg@SCGROUP.BARRNET.NET by www.ccl.net (8.6.9/930601.1506) id OAA22959; Tue, 12 Jul 1994 14:20:11 -0400 Received: from fujitsu1.fai.com by mail.barrnet.net (5.67/1.37) id AA16599; Tue, 12 Jul 94 11:21:11 -0700 Received: from scg.scg.fai.com by fujitsu1.fujitsu.com (4.1/SMI-4.1) id AA17161; Tue, 12 Jul 94 11:20:52 PDT Received: by scg.scg.fai.com (4.1/SMI-4.1) id AA11209; Tue, 12 Jul 94 11:21:34 PDT Date: Tue, 12 Jul 94 11:21:34 PDT From: billg@scg.fujitsu.com (Marketing) Message-Id: <9407121821.AA11209@scg.scg.fai.com> To: chemistry@ccl.net Subject: environ. model summary Dear Netters, Here is the summary of responses to my query regarding environmental modeling, which were extremely helpful. I have since obtained two of the codes (PRZM and GLEAMS) from the EPA and USDA offices listed in the postings below. Many thanks again to all who responded or expressed interest. Bill Glauser --------------------------------------------------------------------------- (Original posting) |Has anyone heard of any of the following codes: | PRZM, GLEAMS, EXAMS, and EPIC |They are presumably used for environmental modeling to |assess the fate of pollutants in the environment. |I am curious as to the models that underlie these codes. |For example, what kinetic, thermodynamic, and transport |models are used to determine how a compound partitions |between the water, ground, and atmosphere? |On a related note, what is the level of maturity of the field |of environmental modeling (probably macroscopic) |versus molecular modeling (microscopic)? |Finally, where can one obtain these codes and on which platforms |do they run? |Thanks in advance for your help. |Bill --------------------------------------------------------------------------- From: bowlus@palres.dnet.sandoz.com (Steve Bowlus) GLEAMS and PRZM (and possibly the others) are soil fate models, commonly used in the pesticide industry for modeling runoff of pesticides from fields. I forget the exact acronyms, but they are something like _G_round _L_oading _E_ffect... and _P_esticide _R_oot _Z_one _M_odel. . .you can get the drift from the names. These are transport models, which depend on the physical properties of the materials being modeled. At this point, the only "molecular modeling" that I have done in the systems is to evaluate physical properties, such as partition coefficients and Henry's constants. Try R.A. Leonard, W.G. Kinsel and D.A. Still, Transac. Am. Soc. Ag. Engineers, vol 30 no. 5 (1987) for a description of GLEAMS. You can get a lot more information about these models from our biologists at our Gilroy test center: talk to Rakesh Jain or Bob Lamoreaux. We use a program called PRE-AP, which is a front end for GLEAMS. Their number is ( 408) 848-1474. sb --------------------------------------------------------------------------- From: Dr. Dave Winkler I would greatly appreciate a summary of the responses. --------------------------------------------------------------------------- From: jim@ni-ait.co.jp (CGI Jim Jones) Bill, My company consults on high-level nuclear waste disposal and we are familiar with most codes related to the environment, but have not heard the four that youmention. There are several places you might try: Energy Science and Technology Software Center e-mail: ESTSC@ADONIS.OSTL.GOV phone: 703-487-4753 Let me know if you don't get what you want from those and I'll see if I can point you to some other places. If you do find out any information on those applications, could you let me know? -------------------------------------------------------------------------- From: gmeier@ncsa.uiuc.edu (Gary Meier) I've had very limited exposure to PRZM (Pesticide Root Zone Model) and GLEAMS (Groundwater Loading Effects of Agricultural Management Systems). The former is available from the U. S. Environmental Protection Agency Center for Exposure Assessment Modeling (CEAM) in Athens, Georgia, (706)-546-3549. The latter is available from the U. S. Department of Agriculture, Agricultural Research Service. Contact J. R. Williams or C. W. Richardson at the Grassland, Soil & Water Research Lab in Temple, Texas, 817-770-6500. As of a year ago, both programs were available without charge (I think they want you to send them blank disks). I believe both programs run only on IBM PCs and clones. I don't know a lot about the models that underly the codes, but PRZM at least permits very detailed modeling of pesticide movement in the surface water, throught the root zone, and in the ground water. Effects of weather, soil and crop types (including crop rotation), irrigation (if used), pesticide application rate and timing, and a host of other parameters are entered. Pesticide movement is calculated using daily time steps in simulations that typically cover several years to several decades. When I was playing with the program, a three-year simulation of low to moderate complexity required just 3 or 4 minutes on a 25 mhz 486 PC. I haven't had opportunity to validate the programs or do any other comparisons to real-world results, so I can't comment on how accurate the simulations are. I hope you find this useful. Gary -------------------------------------------------------------------------- From shawn@wucmd.wustl.edu Thu Jul 7 08:04:17 1994 Please summarize your responses for this interesting question for the net. Thank You. Shawn Huston -------------------------------------------------------------------------- From: gerson@VNET.IBM.COM (Dennis J. Gerson, Ph.D.) Bill, all the codes you mentioned are used in groundwater or underground reservoir modeling. The codes do have chemical knowledge thru group function activity coefficients and fugacities (ala Aspen). The major users of these codes are the oil companies and environmental remediation companies. The codes all run on SGI with OpenGL, IBM RISC with OpenGL they may support Uniras Unigraphics, thus SUN, DEC, HP and IBM. Regards, Dennis Gerson -------------------------------------------------------------------------- From: slee@theochem.uwaterloo.ca (Tom Slee) Hi Bill, I don't know any of the codes you mention. However, my impression is that most environmental models work on a cell basis. You set up your system as a set of cells: one cell may be a lake, one the atmosphere, one the ground nearby, one the fish within the water, etc. (I don't know how coarse or fine these cells can be now). Then you set up differential equations describing the flow of materials of interest from one cell to another (or to nowhere in the case of degradation). These equations may be transport equations, or may represent chemical processes: generally you will have both physical and chemical processes affecting the distribution. Then you solve your system of equations numerically. There are clearly lots of approximations in this kind of model: it is implicit that there is perfect mixing within each cell, and the equations dramatically simplify the factors in determining the distribution. There are also, however, lots of empirical numbers that need to be known and typically are not. The rate of mixing of one "cell" with another must be very dependent on site, and many other rates are not well known, so in the end you have a very empirical model. This about sums up my total knowledge of the subject, so don't ask any questions! Tom From rob@retina.chem.psu.edu Tue Jul 12 17:52:48 1994 Received: from retina.chem.psu.edu for rob@retina.chem.psu.edu by www.ccl.net (8.6.9/930601.1506) id RAA25633; Tue, 12 Jul 1994 17:13:53 -0400 Received: by retina.chem.psu.edu (920110.SGI/1.30) (for CHEMISTRY@ccl.net) id AA21889; Tue, 12 Jul 94 17:14:44 -0400 Date: Tue, 12 Jul 94 17:14:44 -0400 From: rob@retina.chem.psu.edu (Rob Stanton) Message-Id: <9407122114.AA21889@retina.chem.psu.edu> To: CHEMISTRY@ccl.net Subject: vdw params for Cd and Hg Has anyone developed or know of any published vdW parameters for Cd or Hg??? Please respond directly to me and thanks for any help. Rob ____________________________________________________________________________ * * * * * * * Robert V. Stanton * * * * * * * * tel 814-863-7591 * * /\ */\ * email rob@retina.chem.psu.edu /\ /--\/__\ /\ * 152 Davey Lab * /--\/ \ \/--\ Penn State University / / \ / \ Univ. Park, PA 16802 / / \/ \ USA Go Climb a mountain!!!! _____________________________________________________________________________ From ghislain@unb.ca Tue Jul 12 20:52:48 1994 Received: from unb.ca for ghislain@unb.ca by www.ccl.net (8.6.9/930601.1506) id UAA28164; Tue, 12 Jul 1994 20:14:18 -0400 Received: from jupiter.sun.csd.unb.ca by unb.ca (4.1/SMI-4.1-940224-08:05) id AA02176; Tue, 12 Jul 94 21:15:16 ADT Received: from [131.202.47.1] by jupiter.sun.csd.unb.ca (4.1/SMI-4.1-940126-11:10) id AA20968; Tue, 12 Jul 94 21:15:13 ADT Date: Tue, 12 Jul 94 21:15:11 ADT Message-Id: <9407130015.AA20968@jupiter.sun.csd.unb.ca> X-Sender: ghislain@pop.unb.ca Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: CHEMISTRY@ccl.net From: ghislain@unb.ca (Ghislain Deslongchamps) Subject: MM parameters for enolized beta-ketoester Dear CCl'ers Does anyone know where I can find MM2 or AMBER parameters for enolized beta-ketoesters? I need to model a series of compounds containing an enolized 2-carbomethoxycyclopentanone. Thanks Ghis +++++++++++++++++++++++++++++++++++++++++++++++++++++ + Ghislain Deslongchamps, Assistant Professor + + Department of Chemistry + + University of New Brunswick + + Fredericton, N.B. CANADA E3B 5A3 + + e-mail: GHISLAIN@UNB.CA + + phone: 506-453-4795 (or 453-4792) + + FAX: 506-453-4599 + +++++++++++++++++++++++++++++++++++++++++++++++++++++