This paper gives the 1998 self-consistent set of values of the basic consta
nts and conversion factors of physics acid chemistry recommended by the Com
mittee on Data for Science and Technology (CODATA) for international use. F
urther, it describes in detail the adjustment of the values of the subset o
f constants on which the complete 1998 set of recommended values is based.
The 1998 set replaces its immediate predecessor recommended by CODATA in 19
86. The new adjustment, which takes into account all of the data available
through 31 December 1998, is a significant advance over its 1986 counterpar
t. The standard uncertainties (i.e., estimated standard deviations) of the
new recommended values are in most cases about 1/5 to 1/12 and in some case
s 1/160 times the standard uncertainties of the corresponding 1986 values.
Moreover, in almost all cases the absolute values of the differences betwee
n the 1998 values and the corresponding 1986 values are less than twice the
standard uncertainties of the 1986 values. The new set of recommended valu
es is available on the World Wide Web at physics.nist.gov/constants. (C) 19
99 American Institute of Physics and American Chemical Society. [S0047-2689
(00)00301-9].