Novel crystalline forms of (1R,2R)-7-chloro-3-[2-(2,4-difluorophenyl)-2 -hydroxy-1-methyl-3-(1H-1,2,4-triazol-1-yl)propyl]quinazolin-4(3H)-one, pharmaceutical compositions containing these crystalline forms, methods of using these crystalline forms for treating and/or preventing various microbial and/or fungal infections or disorders, and processes for obtaining these crystalline forms. In particular, the present subject matter relates to the specific crystalline Forms I, II, III, IV, V, and VI of (1R,2R)-7-chloro-3-[2 -(2,4-difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazol-1-yl)propyl]quinazolin -4(3H)-one, represented by formula II: