Molecular structure and vibrational spectra of melamine diborate by density functional theory and ab initio Hartree-Fock calculations

The molecular geometry and vibrational frequencies of melamine diborate in the ground state have been calculated using the Hartree-Fock and density functional methods (B3LYP) with 6-31G(d) basis set. The optimized geometric band lengths and bond angles obtained by using HF and DFT (B3LYP) show the best agreement with the experimental data. Comparison of the observed fundamental vibrational frequencies of melamine diborate with calculated results by density functional B3LYP and Hatree-Fock methods indicates that B3LYP is superior to the scaled Hatree-Fock approach for molecular vibrational problems.