Electronegativity Force Field for Prediction of Elastic Moduli

Macroscopic elastic moduli (i.e., bulk modulusand shear modulus) of covalent crystals are mainly determined by microscopicstructures and stiffnesses. Herein, the microscopic bond and angleforce constants of covalent crystals were parameterized from theiratomic electronegativities, which is named the electronegativity forcefield (EFF). Based on this force field, the elastic moduli of covalentcrystals can be directly obtained by molecular mechanics calculations.The calculated moduli for various covalent crystals are generallyconsistent with first-principles calculations, while the computationalcost is reduced by several orders of magnitude, indicating the accuracyand efficiency of the EFF. Finally, we found 25 ultrahigh-moduluscrystals with a bulk modulus greater than 350 GPa, which demonstratesthat this force field can be used for screening of ultrahigh-modulusmaterials from numerous crystal candidates.