LibOMM : Orbital Minimization Method Library

1. Purpose

The library LibOMM solves the Kohn-Sham equation as a generalized eigenvalue problem for a fixed Hamiltonian. It implements the orbital minimization method (OMM), which works within a density matrix formalism. The basic strategy of the OMM is to find the set of Wannier functions (WFs) describing the occupied subspace by direct unconstrained minimization of an appropriately-constructed functional. The density matrix can then be calculated from the WFs. The solver is usually employed within an outer self-consistency (SCF) cycle. Therefore, the WFs resulting from one SCF iteration can be saved and then re-used as the initial guess for the next iteration.

This module is an effort from the Electronic Structure Library Project (ESL), and it was initiated during an E-CAM Extended Software Development Workshop in Zaragoza in June 2016. More information on the module’s documentation can be found here, and the source code is available from the E-CAM Gitlab here. The algorithms and implementation of the library are described in

2. Practical application and exploitation of the module

libOMM is one of the libraries supported and enhanced by the Electronic Structure Infrastructure ELSI [1], which in turn is interfaced with the DGDFT, FHI-aims, NWChem, and SIESTA codes.

[1] The electronic structure infrastructure ELSI  provides and enhances scalable, open-source software library solutions for electronic structure calculations in materials science, condensed matter physics, chemistry, molecular biochemistry, and many other fields [].


Analysis of charge dipole moments in DL_MESO_DPD

This module is a post-processing utility of DL_MESO_DPD, the Dissipative Particle Dynamics (DPD) code from the DL_MESO package, and it processes the trajectory (HISTORY) files to obtain the charge dipole moments of all the (neutral) molecules in the system. For more information see the module documentation here.


Solvers for quantum atomic radial equations

SQARE (solvers for quantum atomic radial equations) is a library of utilities intended for dealing with functions discretized on radial meshes, wave-equations with spherical symmetry and their corresponding quantum states. The utilities are segregated into three levels: radial grids and functions, ODE solvers, and states.

For more information see modules SQARE radial grids and functions, SQARE ODE and SQARE states documentations.



Module ClassMC samples the system phase space using the classical Boltzmann distribution function and calculates the time correlation functions from the sampled initial conditions. For more information check the module documentation here.


Direct MD (on-the-fly) flux/rate in OpenPathSampling

This module, based on OpenPathSampling, calculates the flux out of a state and through an interface, or the rate of the transition between two states, while running a trajectory. For more information check the module documentation here.