Are there any differences between wavefunctions (physics) and atomic orbitals (chemistry)?

Atomic orbitals are the one (or two) electron wavefunctions (or probability distribution functions for one or two electrons) in quantum mechanics, where each probability distribution function is represented by the quantity below. Meanwhile... A wave function or wavefunction is a probability amplitude in quantum mechanics describing the quantum state of a particle or system of particles. Typically, it is a function of space or momentum or rotation and possibly of time that returns the probability amplitude of a position or momentum for a subatomic particle. Mathematically, it is a function from a space that maps the possible states of the system into the complex numbers So theoretically speaking, atomic orbitals are just a subset of all possible wavefunctions for an atom. We only have atomic orbitals that predict the states of one or two electrons. But we can have wavefunctions that (theoretically) predict the state of as many electrons as you want (although this introduces significant complexity, making the wavefunctions too complex to solve through analytic solutions - so we try to solve them computationally) In fact, you can have orbitals/wavefunctions for molecules too. "Just as an atomic orbital is a wavefunction that describes the distribution of an electron around the nucleus of an atom, so a molecular orbital (an MO) is a wavefunction that describes the distribution of an electron over all the nuclei of a molecule." http://www.britannica.com/nobelprize/article-43423 (Thanks to for clarifying some things in the comments)

The atomic orbitals of chemistry are wavefunctions in quantum mechanics. Specifically, they are the eigenfunctions of the square of the orbital angular momentum operator. They are expressed in terms of products of radial components with spherical harmonic functions, which are solutions to the Schrodinger Equation in spherical polar coordinates for a spherically symmetric potential. http://en.wikipedia.org/wiki/Atomic_orbital http://en.wikipedia.org/wiki/Spherical_harmonics And I must take issue with Jim's answer. The wavefunction description of atomic electrons - or any other particles - represents everything that we can potentially know about these particles, and the correspondence with reality is exact. They therefore do represent 'the whole truth' about these phenomena. The only difficulty we have is that we can only solve the Schrodinger Equation analytically for fairly simple atoms; for more complex atoms, the equations must be solved numerically on a computer, but they can still be solved with an arbitrary degree of accuracy (i.e. as accurately as we need). Yes, it is of course true that wavefunctions and atomic orbitals are really just mathematical metaphors and convenient mental pictures of the quantum realm, but they are all we have, and there is no other rival description that can compete with the quantum mechanical one in terms of its predictive power or agreement with empirical data.  To this extent, quantum physics also represents 'the only truth' about such phenomena. If philosophers and mystics think they know more about atoms and subatomic particles than quantum physics can reveal then, please, do tell us - we're all ears :o) Failing that, they should avoid the temptation to nit-pick at quantum physics when they have nothing better to replace it with :o)

wave functions and orbitals are different ways to envision and mathematically describe atomic and sub-atomic particles and states of being that are unknown (and that are currently thought to be unknowable because of the "measurement problem"). Neither completely accounts for all we are able to measure about particles.  X-ray diffraction "shows" particles in specific orbitals in some cases, but those particles fail to act as rigidly and uniformly as we expect from that type of picture, which of course is what finally caused the wave function descriptions. Neither is "real" as such, both are incomplete descriptions.  If 2 people describe the same sunset, or music, or emotion, the words and images they use may be quite different but still allow us to understand.  Wave functions and orbitals are much like those different words and images; both true, but neither the whole or only truth.