n = 4
Lactic acid {0.0783[Sσ] , 0.1061[Sσ] , 0.0032[Sσ] } {-0.0773[Rσ] , -0.0989[Rσ] , -0.0029[Rσ] } 1.1363
Alanine { 0.1149[Sσ] , 0.0311[Sσ] , -0.0015[Rσ]}{-0.1186[Rσ] , -0.0304[Rσ] , 0.0023[Sσ] } 0.6296
For lactic acid and alanine the presence of S and R stereoisomers means that we can also consider the magnitude of the stereoisomeric excess Xσ. We find for lactic acid a preference for the S stereoisomer since Xσ > 1 (= 1.1363), corresponding to values of the chirality Cσ = 0.0783 and Cσ = -0.0773 for the S and R stereoisomers respectively. For alanine the chirality Cσ is much larger than the bond-flexing Fσ contribution for both alanine S and R stereoisomers; the converse is true for lactic acid.
A strong preference for the R stereoisomer is found for alanine due to the presence of the larger magnitude of Cσ = -0.1186 (compared with Cσ = 0.1149 for the S stereoisomer) and Xσ < 1 (= 0.6296), see Table 1(b) .
Table 2(a). For the formally achiral glycine molecule in the absence of an electric (E )-field, the maximum stress tensor projections { bond-twistmax, bond-flexingmax, bond-anharmonicitymax} for the torsional C1-N7 BCP and torsional C1-C2 BCP , wheredr is a finite BCP shift vector, see the caption ofFigure 1 for further details. The connectivity n of the fixed reference C1 atom is indicated.
{ bond-twistmax, bond-flexingmax, bond-anharmonicitymax}