Salman Ahmad Khan

6 Questions 14 Answers 0 Followers

Questions related from Salman Ahmad Khan

How to add a f polarization function to the LANL2DZ basis set in gaussian09?

I am trying to do a calculation using the LANL2DZ basis set with an extra f polarization function. The input line in my gaussian file reads as follows: #p ub3lyp lanl2dz(f) nosymm opt I get the...

05 July 2020 7,535 0 View

How to get force constants in internal coordinates in Gaussian?

I have tried quite a few different ways to get Gaussian to print the force constants in internal coordinates. If the size of the molecule is small then it prints both the internal hessian and...

06 December 2017 5,297 5 View

How to assign dihedral force constants fit from an ab-inito scan to a force field ?

I want to generate the dihedral constants for a force field. Doing a potential energy scan of by rotating around the 2-3 bond using an QM software we can get the variation of the dihedral energy...

09 November 2017 8,695 9 View

Where can I find parameters for all elements for the OPLS Force field?

I have looked through some papers and also on Jorgensen's website, but i cant find parameters for all elements. They also have a web server where you can upload a structure and it will spit out...

04 November 2017 1,611 5 View

How does vacancy concentration affect vacancy migration barrier?

Using VASP I calculated the activation barrier of vacancy diffusion on the surface of ZnO for a 2x2 3 layered cell, where i had removed 1 oxygen atom out of 4 on the surface, and it came out to be...

14 September 2015 2,583 4 View

Does increasing the number of images improve convergence when doing a NEB calculation using VASP? Any other pointers for improving convergence?

I want to calculate the path of diffusion of surface vacancies in ZnO. I was able to get converged results for a 2x2 3 layered cell using 5 images, but the same calculation didn't converge with 3...

07 September 2015 9,854 3 View