Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
(A) Contours of steric contribution: green contour favors steric or bulky group, yellow contour denotes disfavored region. (B) Contours of electrostatic contribution: blue contour indicates electropositive charge, red contour electronegative charge.
