Molecules with more than three atoms are even more complicated and have even more vibrations which are sometimes called "vibrational modes". Each new vibrational mode is basically a different combination of the six shown above. The more atoms in the molecule the more ways they can be combined. For most molecules with N atoms the number of possible vibrations for that molecule is 3N - 6 while linear molecules, or molecules with there atoms in a straight line, have 3N-5 vibrational modes.