1. A. L. Sklar, J. Chem. Phys. 5, 669 (1937).JCPSA60021-9606
2. Symmetry symbols for vibrations are denoted with small Greek letters.
3. H. Sponer, G. Nordheim, A. L. Sklar, and E. Teller, J. Chem. Phys. 7, 207 (1939).JCPSA60021-9606
4. E. P. Carr and H. Stücklen, J. Chem. Phys. 6, 55 (1938).JCPSA60021-9606
5. Personal communication from Dr. H. Stücklen for which we are much indebted.