The crystal structure prediction (CSP) problem, that is, the quest to predict the three-dimensional arrangement of molecules within a crystal lattice from the bare knowledge of the chemical structure, stands out as one of the grand challenges in modern materials science. The Symmetry-Constrained Monte Carlo (SC-MC) algorithm is based on the premise that crystals are highly ordered structures, formed by superimposing symmetry-related arrangements of one or more independent molecules which infinitely repeat in space. The idea is to exploit symmetry to significantly reduce the number of degrees of freedom (DOFs) required to explore the configurational space. Thus, both computational cost and time needed to generate large sets of plausible structures is significantly lowered. The algorithm can indeed run on a standard laptop in a few hours.
The SC-MC program uses MiCMoS algorithms and libraries, and comes with utilities to compare computer-generated structures. The package is released for free for Academic and non-profit users under the Creative Commons CC-BY-NC-SA conditions, and it can be downloaded here upon registration. Industrial and for-profit users are requested to contact Dr.
The SC-MC program, the manual, and the routine to check structure similarity, were written by Dr.
Relevant publications
Seminal paper of the SC-MC method: Giovanni Macetti,* Luca Sironi, Margherita Vacchini and Leonardo Lo Presti. Symmetry-Constrained Monte Carlo for the crystal structure prediction of small organic molecules. 2025, 25, 20, 8382–8392, doi: https://doi.org/10.1021/acs.cgd.5c00537
