The other variable is the basis set; here, we refer to a basis set of one-electron functions (or orbitals), usually centered on the atoms. The electronic Schrödinger equation becomes greatly simplified once we solve it using such a basis. The larger the basis set (the more orbitals it contains), the more accurately we model the Schrödinger equation for the given correlation method. However, even an infinite basis set can give incorrect answers when paired with an approximate treatment of electron correlation. Likewise, even an exact treatment of electron correlation can give terrible answers when paired with a very small basis set. Better and better results can be obtained when one increases the basis set and improves the treatment of correlation. In the limit of an infinite basis set and an exact treatment of electron correlation, the electronic Schrödinger equation would be solved exactly.