Structure Factors (IMAGE) Moscow Institute of Physics and Technology Caption Dependence of calculated structure factors for the two highest occupied molecular orbitals -- HOMO and HOMO-1 -- of the naphthalene molecule on electric field orientation, that is, on the Euler angles β and γ from figure 1. The absolute values of the structure factor are color-coded, with red indicating the minimum values, and yellow and purple indicating the maximum values. The squared absolute value of the structure factor determines the rate of tunneling ionization from a given orbital in the direction opposing that of the field, since the electron is negatively charged. Credit Image courtesy of the researchers Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.