\DeclareMathSymbol{C}{\mathord}{AMSb}{`C}
The first argument is the token (control sequences are valid here) you're defining. The second is the class, \mathord
, \mathbin
, \mathop
, \mathrel
, \mathopen
, \mathclose
, \mathpunct
, and 7 for variable (there's probably some \mathfoo
for variable, but I don't know what it is). The third is the font family. The fourth is the position within that family.
As would be expected, this particular case eventually expands to a \mathcode `C="0.43
. I don't really know what the missing hex digit (the family) is. \mathcode
is one of those mysterious (to me) primitives.
I believe the basic format is: \mathcode `x="cfpp
where x
is any literal character, c
is the class (0 = ordinary through 7 = variable), f
is the family, and pp
is the position within that family. cfpp
is a hexadecimal value, of course.
It occurs to me that you might want to use 7
instead of \mathord
to get a letter in the variable class. I'm not sure. Hopefully someone else can express an opinion on the matter.
Detexify didn't help, so maybe you really have to do it yourself:
\newcommand\simtimes{\mathbin{%
\stackrel{\sim}{\smash{\times}\rule{0pt}{0.9ex}}%
}}
Adjust the 0.9ex
to your needs.
Best Answer
If the scaling is not excessive, the symbol should render well. The optional argument, that tells LaTeX how much to scale horizontally, should not be more than 2.5, otherwise some artifacts will appear. The default value is, as you requested, 1.5.