Molecular structure of 2-methylamino-5-[(5-methyl-2-benzoxazolinone-3-yl) methyl]-1,3,4-thiadiazole dihydrophosphate: A combined X-ray crystallographic and ab initio study

Crystal structure of the compound entitled 2-methylamino-5-[(5-methyl-2- benzoxazolinone-3-yl)methyl]-1,3,4-thiadiazole dihydrophosphate is determined using X-ray analysis and compared with the structure obtained from semiempirical and RHF methods at various levels of theory. RHF/6-31G(d) calculations offer the best conformity with X-ray results for bond lengths and bond angles. Moreover, at the result of the comparison of various combinations of basis sets and methods, it appears that there is not much gain in accuracy by using sophisticated methods.