Angularity is intrinsic to this eq 1. To determine the numbers on the right-hand side (r.h.s.) of eq 1, one must place, e.g., 1 rad for 0, such that the appropriate number can be gotten from tables, obtaining erpi8= cos (1rad)
+ i sin (1red)
or expi8= 0.54
+ 0.84i
(2) Using the number 1in place of 1 rad, one could not know whether one means 1degree or minute or second or radian. Likewise. I rad must be laced into the e x ~ o n e non t the 1.h.s. of eq 2 fo; the angle symbol 8. It is encumbent on the author to unearth the de Moivre derivation and show uneauivocallv that the number replaces the angle unit in the argument o i the sin and cos. The imaginary nature of this equation is important; the symbol i on the 1.h.s. interferes with what is "clear" to the author: that one may not have units in the power of the exp term, since it is logarithmic in nature. In reference t o the third paragraph of the above letter, the author presents such as cos (2svt), cos (2svt 8 ) and cos (wt), attempting t o impose number, rather than angle units, on these expressions. He claims 2n is a number, as is u t ; hence, 2 m t is a number, etc. Since cos (2+), etc., must have angle units in the parenthetical argument, we see that use of proper units for 2a, v, and u lead automatically to proper units radian in the argument as follows:
+
rad
cos (Zs
Y
6cycle.
t
= COB (2wt rad)
Atomlc Orbltals
To the Edltor:
I enjoyed very much reading Nelson's (1) illuminating review on different interpretations of quantum theory with respect to finding explanations for the existence of regions of space with finite probability density separated by nodes where the probability density vanishes. Nevertheless, I found this paper to be marred by a slight ambiguity that might reinforce existing misconceptions. Nelson indicates that the ZD,- orbital remesents an examnle where the above dilemma arises. 1f theip, orbital were tb serve as a building block for the determination of *-orbitals in planar molecules, then the given example might be termed appropriate. If, however, the ZD, orbital were to refer to the 2~ state of a hidrogenicatom,ihen it should be pointed out that the wave function to be used for aproper interpretationof experimental findings should reflect the full symmetry of the point group of the Hamiltonian (2). According to Unsold's theorem (3) the charge distribution in the 2p state of a hydrogenic atom is spherically symmetric. The wave function giving rise t o the spherically symmetric charge distribution can be obtained as a linear combination of the three degenerate orthogonal 2p orbitals. For this linear combination of atomic orbitals the problem with the planar nodes does not exist. Literature cned I Scl??n. P 1; J 1'orm.Educ. 1950.67 441. 2 9rtw P Cnem Pnb8 i r t r 199%IZti.fi3C 1 S a l e r . J C QLnn
