New ab Initio Potential Energy Surfaces for the Renner-Teller Coupled 𝟏^𝟏𝐴^′ and 1^𝟏𝐴^′′ States of CH₂

Table 4

The calculated 𝐽=0 vibronic energy levels of the 𝑎¹𝐴₁ and 𝑏̃¹𝐵₁ states on our ab initio PESs employing the MCTDH method, compared with other theoretical results and experimental values. The energy levels are in cm⁻¹, relative to the zero point energy of the 𝑎¹𝐴₁ state.

𝑎/𝑏̃	𝜈1	𝜈2	𝜈3	Green Jr. et al.^a	Gu et al.^b	Ours	Expt.
𝑎	0	1	0	1356	1351.2	1350.9	1352.6^d
𝑎	0	2	0	2675	2664.1	2666.9	2667.7^d
𝑎	1	0	0	2808	2807.5	2808.9	2806.0^e
𝑎	0	0	1	2863	2864.5	2862.5	2865.0^e
𝑎	0	3	0	3962	3945.6	3950.6	3950.5^d
𝑎	1	1	0	4159	4156.5	4150.4	4152.8^f
𝑎	0	4	0	5216	5191.5	5199.2	5196.6^d
𝑎	1	2	0	5452	5437.6	5444.1	5444.9^f
𝑎	2	0	0	5538	5529.3	5529.3	5531.4^f
𝑎	0	5	0	6430	6397.9	6406.8	6403.0^d,f
𝑎	1	3	0		6706.4	6712.0	6714.1^f
𝑏̃	0	0	0	8383	8354	8349	8350^h
𝑏̃	0	1	0	9566	9537	9534	9537^h
𝑏̃	0	2	0	10848	10831	10828	10827^h,i
𝑏̃	0	3	0	12231	12226	12220	12220^g,i,j
𝑏̃	0	4	0	13681	13684	13673	13678^g
𝑏̃	1	2	0	13850	13840	13835	13834^g
𝑏̃	1	3	0	15116	15121	15106	15114^g
𝑏̃	0	5	0	15317	15326	15313	15319^g
𝑏̃	2	2	0	16749	16749	16738	16742^k
𝑏̃	0	6	0	16929	16948	16934	16941^c,g
𝑏̃	1	5	0	18186	18201	18182	18192^k
𝑏̃	0	7	0	18590	18617	18603	18610^c,g

^aFrom [17]. ^bFrom [19].^cFrom [58]. ^dFrom [8]. ^eFrom [11]. ^fFrom [59]. ^gFrom [2]. ^hFrom [10]. ⁱFrom [12]. ^jFrom [9]. ^kFrom [60].