Table 3: Ground-state 1 Σ + 𝑔 of Z n 2 dimer.

𝑅 𝑒 (Å) 𝜔 𝑒 (cm−1) 𝐷 𝑒 (eV)

exp125.70.034
exp24.1925.90.035
HF-MP2Q3.611290.049
srLDAMP2Q3.445 310.0459
PBEQ3.157480.678
PBE3.156490.683
PBE0dissdissdiss
BPW913.225410.0154
BP863.181460.036
BLYPdissdissdiss
B3LYPdissdissdiss
GRAC-PBE03.33840.00.045
CAMB3LYP4.219110.001
LDA2.846850.225
a3.959220.024
b3.9622.50.030
c14.0320.40.0205
c24.0320.40.0205

pw using aug-cc-pVTZ basis set and SFH. Qaug-cc-pVQZ basis set, for PBE, HF-MP2 and srLDAMP2 (NR with parameter 𝜇 = 0 . 5 ), see text: 1[86]; 2[85]. a[12] using CCSD(T) in pseudopotential. b[17] using NR-CCSD(T). c1[13] CCSD(T) with 4-comp. DCH. c2[13] CCSD(T) with SFH.