Authors

Lily Gunning

Publication Date

4-22-2022

Faculty Advisor

Dr. W. Paige Hall

College/School

College of Arts & Sciences

Department

Chemistry & Biochemistry

Abstract

Six major anthropogenic greenhouse gases: methane (CH4), 1,1,1,2-tetrafluoroethane (C2H2F4), carbon tetrafluoride (CF4), dichlorofluoromethane (CHFCl2), sulfur hexafluoride (SF6), and nitrogen trifluoride (NF3) were computationally modeled using the Gaussian 16 package and 9 different method and basis set combinations. The Gaussian 16 package and 9 different method and basis set combinations were additionally used to obtain IR frequencies and intensities for each of the six anthropogenic greenhouse gases. These values were used to calculate the 20-, 100-, and 500 – year global warming potentials of each gas relative to CO2. Average percent error across the six gases and standard deviation of the percent error were calculated for each level of theory to determine which yielded greatest agreement with literature GWP values that had been calculated using experimental IR spectra. With an average percent error of 46.40% and a standard deviation of percent error of 72.11. The B3LYP/6-31G** or B3LYP/6-31G(d,p) method and basis set combination yielded the greatest agreement with literature GWP values across all three time horizons. The process and calculations described here were further developed into a student handout and lab materials for use in an undergraduate physical chemistry curriculum.

Subjects

Molecules--Models--Computer programs; Greenhouse gases--Research; Climatic changes--Measurement

Publication Information

Copyright for this work retained by the author.

CHM 493H: Senior Honor's Project

Document Type

Student Project

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