Table 1.

The total number of symmetry-allowed first- and second-order average Hamiltonian terms in the R2_n^v (n, v = 1 and 2) symmetry sequences.

Symmetry sequences	Number of symmetry-allowed terms
	${\overline{H}}_{IS}^{(1)}$	${\overline{H}}_{II}^{(1)}$	${\overline{H}}_{I\times IS}^{(2)}$	${\overline{H}}_{II\times IS}^{(2)}$
R212	6	10	96	208
R211	6	10	96	208
R222	0	20	96	208
R221	8	12	96	208