Newton solver method not implemented?

[Woohyeon Baek]

Greetings to Environ users and developers,

I tried using different types of solvers for my QE calculations with Environ and I got the error running when the SCF cycle enters the Environ running with newton solver.

     stopping ...
     Error in routine poisson_charges (1): or environ generalized_charges (1)
     Not implemented

Does newton solver not implemented for Poisson and genearlized Poisson calculations?

Sincerely,

Woohyeon

[andr...@gmail.com]

Hi Woohyeon,

Thanks for the question, the Newton solver is implemented for non-linear electrostatic problem, in particular for the Poisson-Boltzmann problem as needed for charged surfaces in an electrolyte. However, the normal Poisson problem is a linear problem in vacuum and the generalized Poisson model is a linear dielectric model, so there is no need for non-linear solvers. Gradient descent and fixed-point iteration algorithms are more than enough in this case.

Hope this helps.

Best,

Oliviero

Oliviero Andreussi (he/him)
--
Associate Professor
Department of Chemistry and Biochemistry
Boise State University
Office: SCNC 316
Email: oliviero...@boisestate.edu
Web: http://www.materialab.org