From chemistry-request-: at :-www.ccl.net Thu Aug 13 22:01:24 1998 Received: from copland.udel.edu (copland.udel.edu [128.175.13.92]) by www.ccl.net (8.8.3/8.8.6/OSC/CCL 1.0) with ESMTP id WAA19006 Thu, 13 Aug 1998 22:01:24 -0400 (EDT) Received: from localhost (stlin;at;localhost) by copland.udel.edu (8.8.8/8.8.8) with SMTP id WAA18405 for ; Thu, 13 Aug 1998 22:01:25 -0400 (EDT) Date: Thu, 13 Aug 1998 22:01:25 -0400 (EDT) From: Shiang-Tai Lin Reply-To: Shiang-Tai Lin To: Computational Chemistry List Subject: Solvation calculation in Gaussian 94 Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Dear CCL users, I was trying to use G94 to do some solvation calculations and had difficulty in understanding the meanings of some of the output lines. I appreciate any of your help. In the input file, I wrote #T rhf/6-31g(d) scrf=ipcm volume test The output due to the keyword "volume" are Box volume = 2398.137 fraction occupied=1.000 Molar volume = 2398.137 bohr**3/mol (214.007 cm**3/mol) Recommended a0 for SCRF calculation = 5.34 angstrom ( 10.08 bohr) Question (1): What's the shape of the box? Question (2): How to calculate a0 from the molar volume? It seems to me that the formula (molar volume/Pi)^(1/3)+0.94 bohr is used. But why? The some of the output due to scrf=ipcm are Max. Dist. Between Center of Nuclear Charge and Isosurface = 5.222190E+00 Min. Dist. Between Center of Nuclear Charge and Isosurface = 3.402845E+00 Total "Solvent Accessible Surface Area" of Solute = 2.467157E+02 Volume of Solute Cavity = 3.391144E+02 Question (3): What are the units of these values? Question (4): Where can I find references that explains how to calculate these values? Thank you. Shiang-Tai Department of Chemical Engineering University of Delaware (O) (302) 831-6857 (H) (302) 368-8388 E-mail: stlin _-at-_)udel.edu