I'm now studying the quantum chemistry calculation and Gaussian basis set. For example, when using the 6-31G basis set, the C atom has 6 basis functions in 1s orbital , 3+1=4 in 2s, 3+1=4 in 2px, 3+1=4 in 2py, and 3+1=4 in 2pz; the O atom also has 6 basis functions in 1s orbital , 3+1=4 in 2s, 3+...