Atomic Forces from Electron Density

feature-request
11

Thanks for the explanation. It turns out that this is not the function I want, so sorry for the run-around. All that I’m really looking for is the overlap integral derivative of each individual AO on a nuclear center. I know this is not directly an operation that shows up in mainstream QM methods, but I was hoping I might be able to highjack something.

If nothing else, thanks for helping me understand the code, @jmisiewicz. I will leave a concise statement of the problem below in case anyone happens to come along with some new insight into my problem.

Problem Statement:
I want to compute the following integral to compute the force on a nucleus, i, due to an electron density represented in an auxiliary atomic basis:

F_i = sum_j(integral(Z_i * c_j * X_j / R dv) )

Here, the sum is over the j basis functions, X, and coefficients, c, and the integral is over all space.
There are two problems to be solved here:

  1. Read in the auxiliary basis and coefficients. This is referenced in this post.

  2. Compute the integral above.