The infrared and Raman spectra of 1,3-bis(4-piperidyl)propane molecule have been recorded between 4000-400 cm(-1) region and 3500-150 cm(-1) region, respectively. The vibrational frequencies of the molecule are investigated. The molecular geometry and vibrational frequencies of 1,3-bis(4-piperidyl)propane (also named 4,4'-trimethylenedipiperidine (TMDP)) in the ground state have been calculated by using density functional methods (B3LYP and BLYP) with 6-311 G(d,p) and 6-31 G(d) as basis sets. The comparison of the observed fundamental vibrational frequencies of 1,3-bis(4-piperidyl) propane and calculated results by density functional B3LYP and BLYP methods indicates that B3LYP is superior to the scaled BLYP approach for molecular vibrational problems. (C) 2008 Elsevier B.V. All rights reserved.