I am using the pss(b) template, which starts with,

\documentclass[pss]{wiley2sp} % provides pss two-column style
%\usepackage{bm}              % uncomment these two packages if you
%\usepackage{w-greek}         % need extended greek-letter functionality in math mode

I always got this warning:

Package amsmath Warning: Unable to redefine math accent \vec.

Does anyone know how to fix this problem?


2 Answers 2


load amsmath first:

\documentclass[pss]{wiley2sp} % provides pss two-column style

Then amsmath defines the \vec at first and wiley2sp will redefine it.

  • Your answer was flagged as too short. Could you edit and give some more information? Thanks.
    – LaRiFaRi
    Jun 23, 2015 at 9:00
  • 15
    This also fixes a similar problem with the llncs document style. Many thanks (:
    – drevicko
    Mar 12, 2016 at 9:21
  • Great! solved my problem again :)
    – Alisa
    Feb 18, 2019 at 0:06

This "problem" is inherent to the class you're using.

Here's what's happening: You load wiley2sp, which sets up the document structure. It also (re)defines the macro \vec:


This will print \vec{<stuff>} in bold math font. Yes, it actually redefines the macro from a former \mathaccent to the above.

Now you load amsmath, which cycles through a number of math accents and reconfigures them. Here's an extract from the actual code:

\def\@tempb#1>#2#3 #4\@nil#5{%
      Unable to redefine math accent \string#5}%

The above code is prefaced by the following documentation:

We redefine the standard math accent commands call \mathaccentV, using the mathgroup/encoding-number information embedded in their previous definitions. If the definition of an accent command does not have the expected form, we leave the accent command alone, but give a warning.

You'll notice the set of redefinitions require the former definition of the math accent to start with \mathaccent (as part of the \ifx condition in \@tempb). Since wiley2sp redefined \vec to mean something completely different (not a \mathaccent anymore), amsmath reports the warning.

A way around this would be to capture the definition of \vec before wiley2sp redefines it, and restore it before amsmath checks to redefine it. The following achieves this:

\let\oldvec\vec% Store \vec in \oldvec
\let\vec\oldvec% Restore \vec from \oldvec

Note that, if this is a publisher-related style or class, they most likely want their \vectors printed in a specific format. So, removing this formatting of \vectors is probably not advised.

  • It seems that this way can go around the problem. But it has new problem:! LaTeX Error: Option clash for package graphicx. See the LaTeX manual or LaTeX Companion for explanation. Type H <return> for immediate help. ... l.9 \usepackage {color} ? Here are my codes: \let\oldvec\vec% Store \vec in \oldvec \documentclass[pss]{wiley2sp} % provides pss two-column style \let\vec\oldvec% Restore \vec from \oldvec \usepackage{amsmath} \usepackage[dvips]{graphicx}% Include figure files % \usepackage{amsmath,array} \usepackage{color}
    – user2045447
    Mar 13, 2013 at 6:56
  • Looks like it complains the packages I used below amsmath.
    – user2045447
    Mar 13, 2013 at 7:00
  • 1
    @user2045447: Drop the [dvips] option for graphicx. It will figure out what driver you need based on the compilation sequence. For example, if you are using pdflatex, you can't use [dvips].
    – Werner
    Mar 13, 2013 at 14:13

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