From owner-chemistry@ccl.net Fri May 18 13:35:01 2007 From: "Andrew Joseph Adamczyk a-adamczyk---northwestern.edu" To: CCL Subject: CCL:G: Defining quadrupole in Gaussian 03 Message-Id: <-34302-070518131259-23069-XaIfD05ozq7VN1FcwXffMg++server.ccl.net> X-Original-From: "Andrew Joseph Adamczyk" Date: Fri, 18 May 2007 13:12:56 -0400 Sent to CCL by: "Andrew Joseph Adamczyk" [a-adamczyk]=[northwestern.edu] Hello Everyone, Ultimately I want to assign the charges for the quadrupole moment in N2 against the bias in Gaussian described below (or perhaps persuade against the bias). That is, I am able to generate the quadrupole tensor which has nonzero components Qxx, Qyy, and Qzz. The latter of which is the calculated quadrupole moment for N2. This is with the bias that the quadrupole is of -++- conformation. I also ran the pop=chelpg option and received the following output which only constrains the dipole moment giving zero partial charges: Breneman (CHELPG) radii used. Generate Potential Derived Charges using the Breneman model, NDens= 1. Grid spacing= 0.300 Box extension= 2.800 NStep X,Y,Z= 20 20 24 Total possible points= 9600 Number of Points to Fit= 3328 ********************************************************************** Electrostatic Properties Using The SCF Density ********************************************************************** Atomic Center 1 is at 0.000000 0.000000 0.554640 Atomic Center 2 is at 0.000000 0.000000 -0.554640 3328 points will be used for fitting atomic charges Fitting point charges to eletrostatic potential Charges from ESP fit, RMS= 0.00536 RRMS= 1.00000: Charge= 0.00000 Dipole= 0.0000 0.0000 0.0000 Tot= 0.0000 1 1 N 0.000000 2 N 0.000000 If anyone is able to manipulate Gaussian to allow for unique quadrupole arrangements (with point charges perhaps) in an effort to generate the electrostatic potential surface, your suggestions would be greatly appreciated. Thank you in advance.