A common approach for generating the starting model is the method of Wooten, Winer, and Weaire . The WWW algorithm is a bond switching Monte Carlo approach: a Monte Carlo move is the exchange of two bonds, followed by a structural relaxation (either MD or MC of the newly connected structure). In the case of silicon, you would start from a large cell of diamond cubic Si, and go through a simulated annealing procedure. To generate a starting model of amorphous silica (SiO$_2$), the completed model of amorphous Si can be decorated with oxygen atoms at the midpoints of the Si--Si bonds, then run through a structural relaxation.
The quench-from-the-melt molecular dynamics approach has been rather successful; however, struggles more with a limited box size for the structural solution . Regardless of approach, these starting structural solutions are compared against the pair distribution function (attained from a total scattering experiment) for verification.
From the resulting models, ab initio electronic structure methods can be used to calculate properties of interest. A modern use of these methods with amorphous metal-organic frameworks has been accomplished with zinc imidazolate .
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- A. Tilocca, J. Chem. Phys. 139, 114501 (2013).
- P. Adhikari, J. Phys. Chem. C 120, 15362 (2016).