A basis set in theoretical and computational chemistry is a set of functions (called basis functions) which are combined in linear combinations (generally as part of a quantum chemical calculation) to create molecular orbitals.
Introduction. In the spring of 1861, decades of simmering tensions between the northern and southern United States over issues including statesâ rights versus federal authority, westward expansion and slavery exploded into the American Civil War (1861-65).
Reconstruction. 1  The period after the Civil War, 1865 - 1877, was called the Reconstruction period. 2  In January 1865, Congress proposed an amendment to the Constitution which would abolish slavery in the United States. 3  The Civil War ended on April 9, 1865.