M. Head-Gordon and T. Head-Gordon, “Analytic MP2 Frequencies Without Fifth Order Storage: Theory and Application to Bifurcated Hydrogen Bonds in the Water Hexamer,” Chem. Phys. Lett., 220 (1994) 122-28. DOI: 10.1016/0009-2614(94)00116-2
M. Head-Gordon and T. Head-Gordon, “Analytic MP2 Frequencies Without Fifth Order Storage: Theory and Application to Bifurcated Hydrogen Bonds in the Water Hexamer,” Chem. Phys. Lett., 220 (1994) 122-28. DOI: 10.1016/0009-2614(94)00116-2
