An Investigation of a Combined Thiourea and Hexamethylenetetramine as Inhibitors for Corrosion of N80 in 15% HCl Solution: Electrochemical Experiments and Quantum Chemical Calculation

Table 4

Quantum chemical parameters derived for different inhibitors.

Inhibitors	Total energy	HOMO	LUMO
	(kJ mol^−1)	(kJ mol^−1)	(kJ mol^−1)	(kJ mol^−1)	(debye)	(kJ mol^−1)	(kJ mol^−1)		(kJ mol^−1)
TU	1.47 × 10^6	−483.6	−51.2	432.5	3.545	483.6	51.2	267.4	216.3	0.45
HMTA	−1.29 × 10^6	−477.6	98.3	575.9	0.014	477.6	−98.3	189.7	287.9	0.47