minichem

A very simple quantum chemistry program.

Minichem is a tiny educational project, created in order to better understand the computational methods of quantum chemistry. I will improve it while studying new methods. For details, see A. Szabo, N. Ostlund, "Modern Quantim Chemistry", and T. Helgaker, P. Jorgensen, J. Olsen, "Molecular Electronic-Structure Theory". All example calculations were validated using NWChem.

Features:

• Single-point energy calculation;
• RHF and UHF methods;
• DIIS convergence acceleration algorithm;
• OpenMP parallelization (not yet implemented in C++ version);
• Available elements: all periodic table (but only non-relativistic treatment is available!);
• Available basis sets: cartesian and spherical with L up to g-functions;
• Own scripting language QuantumScript, which is used in input files;
• Tiny basis set library (adopted from EMSL [2,3]).

Possibilities to be implemented in the future:

• DIIS implementation for UHF;
• More scalable OpenMP parallelization;
• Analytic gradients and geometry optimization;
• Projection population analysis;
• I want to try to implement four-index transformation, MP2, CISD, CCSD and CCSD(T) energies, CISD transition dipole moments, EOM-CCSD.

How to compile:
$ cd src
$ make
$ make install
To compile minichem, you need LIBINT[1] and Eigen libraries installed on your machine and any C++ compiler (I use g++ on my laptop). For more details about installation of external libraries, see src/Makefile and docs/manual_ru.pdf (in Russian) for details.

How to uninstall:
$ cd src
$ make uninstall

For suggestions and questions, [email protected], I look forward to any comments!

Citations

[1] LIBINT: A library for the evaluation of molecular integrals of many-body operators over Gaussian functions, Version 2.1.0 (beta) Edward F. Valeev, http://libint.valeyev.net/ .
[2] The Role of Databases in Support of Computational Chemistry Calculations Feller, D., J. Comp. Chem., 17(13), 1571-1586, 1996.
[3] Basis Set Exchange: A Community Database for Computational Sciences Schuchardt, K.L., Didier, B.T., Elsethagen, T., Sun, L., Gurumoorthi, V., Chase, J., Li, J., and Windus, T.L. J. Chem. Inf. Model., 47(3), 1045-1052, 2007, doi:10.1021/ci600510j.