Table 2.

The values of electron density (ρ), its Laplacian (∇2ρ), the energy of hydrogen bonding $\left(E_{\mathit{HB}}\right),$ bond length, and different charge (D.C) for hydrogen bonding between ASP surfactants.

Compounds	Atoms	$\rho$	${\mathrm{\nabla }}^2\rho$	$E_{\mathit{HB}}(\text{kj}{\text{mol}}^{-1})$	$r(\text{nm})$	$D.$C
ASP-SDBS	$S-O\cdots H-N$	0.036	0.032	42	0.18	1.53
ASP-SDS	$S-O\cdots H-N$	0.038	0.035	48	0.17	1.52