Potential Functions and Thermodynamic Properties of UC, UN, and UH

Table 1

Parameters of potential functions of UC, UN, and UH^a.

Compound	Function	Methods	Parameters		R-square	RMSE
UC	Morse	CI	De = 5.153	β = 1.47	0.9913	0.6759
		PBE1	De = 5.152	β = 1.583	0.9988	0.2734
		CCSD	De = 6.269	β = 1.508	0.9911	0.8428
		QCISD (T)	De = 6.387	β = 1.501	0.9916	0.8534
	L-J	CI	A = 97.4	B = –32.43	0.8713	2.6000
		PBE1	A = 88.4	B = –40.76	0.8832	2.6440
		CCSD	A = 100.5	B = –34.77	0.8489	3.4820
		QCISD (T)	A = 101	B = –34.45	0.8505	3.6080
	Rydberg	CI	De = 5.368	β = 2.135	0.9901	0.7198
		PBE1	De = 5.333	β = 2.305	0.9974	0.3938
		CCSD	De = 6.424	β = 2.197	0.9881	0.9788
		QCISD (T)	De = 6.551	β = 2.186	0.9889	0.9840
UN	Morse	CI	De = 3.161	β = 2.535	0.9736	1.2290
		PBE1	De = 5.08	β = 1.79	0.9972	0.3866
		CCSD	De = 4.197	β = 2.06	0.9585	1.5640
		QCISD (T)	De = 4.186	β = 2.031	0.9887	0.8275
	L-J	CI	A = 111.1	B = –32.01	0.9253	2.0670
		PBE1	A = 130.7	B = –18.98	0.8864	2.4540
		CCSD	A = 114.2	B = –30.18	0.9201	2.1710
		QCISD (T)	A = 115.4	B = –29.58	0.9159	2.2540
	Rydberg	CI	De = 3.951	β = 3.94	0.9591	1.5300
		PBE1	De = 5.289	β = 2.603	0.9968	0.4096
		CCSD	De = 4.271	β = 2.977	0.9584	1.5650
		QCISD (T)	De = 4.422	β = 2.951	0.9573	1.6060
UH	Morse	PBE1	De = 2.535	β = 1.326	0.9874	0.2750
		CCSD	De = 2.265	β = 1.29	0.9859	0.2769
		QCISD (T)	De = 2.643	β = 1.235	0.9940	0.1925
	L-J	PBE1	A = 40.08	B = –0.0883	0.6342	1.4820
		CCSD	A = 35.27	B = –2.884	0.6777	1.3260
		QCISD (T)	A = 39.82	B = –0.08717	0.6199	1.5330
	Rydberg	PBE1	De = 2.612	β = 1.921	0.9906	0.2371
		CCSD	De = 2.339	β = 1.87	0.9885	0.2505
		QCISD (T)	De = 2.707	β = 1.79	0.9950	0.1751

^aUnit of D_e and RMSE is eV, the unit of β is Å⁻¹, and the units of A and B are eV∙Ź² and eV∙Å⁶.