XS hash question

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calculate('V_MIN',4.5);

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calculate(NAME => 'V_MIN',
          THETA => 4.5);

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int
calculate(hash)
...
  RETVAL = 1;
OUTPUT:
  RETVAL

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ChemC.xs: In function `XS_ChemC_calculate':
ChemC.xs:122: parse error before `char'
...
ChemC.xs:125: for each function it appears in.)
ChemC.xs:126: `theta' undeclared (first use in this function)
make: *** [ChemC.o] Error 1

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