# How to extract wavefunction from GAMESS output?

Is there a way to extract the molecular wavefunction from GAMESS output?

I know there are packages that can extract the eigenvalues or the exponents and show them as a table but that is not of much help as anyone can easily find those values in the output file by looking at the numbers.

What I am looking for is the complete wavefunction equation. Is there such a package or something available. Something like this simple extractor I have written for STO-3G (this is just a very primitive one that only works for small STO-3G outputs ) :

• What kind of calculation your doing(SCF/CI/MCSCF/MPPT)? How large? The numbers are in a few different places and the actual wave function can easily have millions or billions of terms and shouldn't need to be written down in this form if it is any system of real value. Apr 16 '15 at 22:10
• @XiaoleiZhu It is SCF and the basis set is 6-311. The system is not that large ( maybe just ~100-150 orbitals )
– Aug
Apr 16 '15 at 22:27
• 100 orbital can be difficult to handle in Mathematica. Say you have 20, electrons, then it is a 20x20 determinant, each element of which is a 100 term summation of AO, and each AO is a summation of from 1 to 6 Gaussian functions multiplied by an angular part. Apr 17 '15 at 0:17
• If you specify what you want to do with the wave function, then we can probably provide more help. There is nothing that generate Mathematica code from GAMESS output as far as I know, but there are a number of programs that can extract the wave function and calculate properties or plot orbitals for you. I can try to show you how to write a program to do it, but I am not sure if it will worth the effort. Apr 17 '15 at 0:31
• @XiaoleiZhu What I want to do is related to my other question that you answered ( calculation of molecular volume based on that wavefunction ). Now I am trying to find my molecular dimensions and topography ( not just the volume ). In Gaussian I could calculate the volume based on 0.001 e/bohr but it is just the volume. I need the dimensions for example at 0.05 e/bohr. even arbitrary dimensions can help me a lot .
– Aug
Apr 17 '15 at 1:33