Table 1.

Calculated vertical excitation energies (eV) of TMBODIPY derivative (a) for the monomer and $\pi$-stacking dimer by spin-flip LC-TDBLYP, LC-TDBLYP (monomer) and TD$\omega$B97XD (dimer) with cc-pVTZ basis sets and CPCM solvent effect of acetonitrile.

Excited state	Exp.a		SF-LC-TDBLYP			LC-TDBLYP/TD$\omega$B97XD
	eV	nm	Main transitions	eV	nm	eV	nm	f
Monomer in acetonitrile
T${}_1$				1.54	806	1.44	861
S${}_1$	2.47	501	$\left\{\begin{array}{c}\text{H}\to \text{L}(-0.71)\hfill \\ \text{H}\to \text{L+1}(0.69)\hfill \end{array}\right)$	2.21	562	2.97	418	0.5804
S${}_2$			$\left\{\begin{array}{c}\text{H}-1\to \text{L}(-0.86)\hfill \\ \text{H}\to \text{L}(-0.29)\hfill \end{array}\right)$	3.30	376	4.01	309	0.0880
$\mathit{\pi }$-Stacking dimer in acetonitrile
T${}_1$				1.55	802	1.38	899
${}^5$(TT)${}_1$	2.99	415				2.76	449
S${}_1$	2.47	501	$\left\{\begin{array}{c}\text{H}\to \text{L+3}(0.68)\hfill \\ \text{H}-1\to \text{L}(0.65)\hfill \end{array}\right)$	2.20	564	2.76	450	0.1194
S${}_2$			$\left\{\begin{array}{c}\text{H}-4\to \text{L}(0.49)\hfill \\ \text{H}-2\to \text{L}(0.45)\hfill \end{array}\right)$	3.22	385	2.93	423	0.9479
S${}_3$			$\left\{\begin{array}{c}\text{H,H}\to \text{L,L}(0.98)\hfill \\ \text{H,H}\to \text{L,L+1}(-0.12)\hfill \end{array}\right)$	3.34	371	3.69	336	0.0158
S${}_4$			$\left\{\begin{array}{c}\text{H}-5\to \text{L}(-0.69)\hfill \\ \text{H}-4\to \text{L}(-0.49)\hfill \end{array}\right)$	3.54	351	3.69	336	0.0052

^aRef.¹².

Main transitions of spin-flip LC-TDBLYP excitations are also shown with the coefficients of the response functions in parentheses, in which the notations H and L indicate HOMO and LUMO. The oscillator strengths (f) of LC-TDBLYP (monomer) and TD$\omega$B97XD (dimer) are also listed.