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Wednesday, June 28, 2006 v0.1

It can be very useful to obtain value of some molecular properties in electric field. I.e. you can get dipole moment of excited states from energies in fields F and -F, hyperpolarizability from analytic polarizability etc. But it's quite annoying to create many very similar Gaussian input files, so I wrote short script to created this files:
#!/usr/bin/env bash
for i in $*
        name=`basename $i .com`
        sed -e '/^%/d; /^#/s/$/ Field=X-10/' $i > ${name}
        sed -e "/^%/d; /^#/s/$/ Field=X+10/" $i > ${name}

Monday, June 05, 2006

No CIS(D) in solvent [Gaussian]

I tried to calculate excitation energy with CIS(D) method in solvent (PCM method). I found that the CIS resalts from CIS and CIS(D) outout are different. I checked and CIS with Direct and without this option gave another results. I wrote to Gaussian Help and got replay: Yes, there are differences and the CIS=Direct results are correct.The non-direct methods, both CIS and CIS(D) use MO integrals where the solvent effects are not present and thus neither of them will give the correct results. Starting with G03 Rev. D the program correctly forces the use of CIS=Direct when combined with solvation. There is no option for doing CIS(D) with solvent and I don't expect this to change. Sorry for any confusion.