Search found 13 matches

by Mdeible
Fri May 27, 2016 6:54 pm
Forum: The CASINO program
Topic: How to determine multideterminant coefficients ?
Replies: 10
Views: 25916

Re: How to determine multideterminant coefficients ?

Hi MinjiaZhao, It may be true that optimizing the determinants simultaneously with the Jastrow factor will effect the parameters of the Jastrow factor. However, if this is the only effect you are seeing, it won't make any difference to the DMC energy. The Jastrow factor has no impact on the nodal st...
by Mdeible
Fri May 27, 2016 12:21 pm
Forum: The CASINO program
Topic: How to determine multideterminant coefficients ?
Replies: 10
Views: 25916

Re: How to determine multideterminant coefficients ?

Hi MinjiaZhao, In general, for anything but the smallest system with only a few determinants, the coefficients won't optimize to a specific value. If they did, we would know the optimized coefficients a priori, and wouldn't need to run the optimization. The coefficients are optimized at the same tim...
by Mdeible
Thu May 19, 2016 2:50 pm
Forum: The CASINO program
Topic: How to determine multideterminant coefficients ?
Replies: 10
Views: 25916

Re: How to determine multideterminant coefficients ?

MinjiaZhao, Well, for a simple system with few determinants, you can write the determinants by hand and pick reasonable coefficients. You'd then follow the same optimization scheme mentioned above. For any system with more than a few determinants, you need to figure out how to get determinates from ...
by Mdeible
Thu May 19, 2016 12:41 pm
Forum: The CASINO program
Topic: How to determine multideterminant coefficients ?
Replies: 10
Views: 25916

Re: How to determine multideterminant coefficients ?

Hi MinjiaZhao, You should have determinant coefficients from your trial wave function, like a CASSCF or CI calculation in Gaussian or GAMESS. These should be copied to the correlation.data file as shown in the manual. Then, run a VMC optimization calculation. These will give you the optimized determ...
by Mdeible
Wed Nov 11, 2015 1:53 am
Forum: The CASINO program
Topic: Molecules adsorbed on metal surfaces
Replies: 2
Views: 8501

Molecules adsorbed on metal surfaces

Hi, I've recently become interested in studying molecules adsorbing to metal surfaces. I have read some of the recent work by Tkatchenko and others discussing the issues with DFT for describing this interaction. It seems to me that DMC would be an excellent method for studying these types of systems...
by Mdeible
Thu Aug 06, 2015 4:43 pm
Forum: The CASINO program
Topic: VMC energy doesn't equal SCF one.
Replies: 7
Views: 15367

Re: VMC energy doesn't equal SCF one.

Hi, Can you also state what molecule you are using? I have seen this problem before as well, where the gaussian_cusp_correction gives clearly erroneous values for the VMC calculation but the general purpose scheme gives reasonable values. I don't have specific data on hand, but I seem to recall it h...
by Mdeible
Mon May 25, 2015 4:16 pm
Forum: The CASINO program
Topic: CASSCF computation
Replies: 8
Views: 14928

Re: CASSCF computation

Also, you haven't given the complete input here. guess=alter means that Gaussian is looking for a list of orbitals to rotate after the xyz coordinates. I'm assuming you have an output generated that list determinants and weights, meaning there is more to your input file?

Mike
by Mdeible
Sun May 24, 2015 2:28 pm
Forum: The CASINO program
Topic: CASSCF computation
Replies: 8
Views: 14928

Re: CASSCF computation

Hi,

It sounds like you are using an old version of CASINO, which includes the old converter. If you use the most recent version of CASINO, it should work with G03 and G09.

What version of Gaussian and CASINO are you using?

Mike
by Mdeible
Fri May 01, 2015 8:35 pm
Forum: The CASINO program
Topic: molden2qmc
Replies: 45
Views: 346158

Re: molden2qmc

Hi, Thanks for taking a look at this Vladimir. I know that the original script that I wrote wasn't the prettiest piece of code, and I'm sure some updates would be helpful. If you want to send me wave functions files to run the tests I can also help out with that. If you want help checking off things...
by Mdeible
Sun Apr 19, 2015 12:02 am
Forum: The CASINO program
Topic: Cubane (C8H8) VMC
Replies: 7
Views: 15338

Re: Cubane (C8H8) VMC

Hi, I have had issues with the Molden files produced by Orca in the past, like I said in the README file. Despite that, I think it's actually performing the way it should in this case. I ran the same calculation in Gaussian09B and Orca v3.0.1. I took the geometry from http://cccbdb.nist.gov/, becaus...