Error in an Approximate Wave Function and an Error Minimization Scheme

摘要

an estimateof error in an approximate wave function for a stationary stte is put forward that does not require any information about the exact state.The measure is sensitive and direct.Parameters embedded in a trial wave functional can be varied to minimize this error as well,leading to a variational principle.Such a scheme works neicely for bound sttes and the more so for Siegert states,for which the standard energy minimization principle does not apply.Pilot calculations on the anharmonic oscillator system and the radial Stark effect in the hydrogen atom reveal the worth of the endeavor.