H2在求解器中如何表示/如何在求解器中输出H2的参数？

[luca]

各位前辈们好：
我在YEqn.H 中定义了所有组分的一个反应速率

    forAll(Y, i)
    {
        ROP_[i].field() = -(reaction->R(Y[i])()).source();
    }

在求解时能正常输出：

但是当我直接定义 H2的反应速率：

ROP_[H2].field() = -(reaction->R(Y[H2])()).source();

编译的时候就报错：

/home/zhu/OpenFOAM/OpenFOAM-2.4.0/src/OpenFOAM/lnInclude/GeometricField.C:188:1: note:   candidate expects 4 arguments, 1 provided
In file included from AMRreactingLMFoam.C:51:0:
createFields.H:287:13: error: expected unqualified-id before ‘(’ token
     thermo. (reaction->R(Y[1])()).source()()
             ^
In file included from AMRreactingLMFoam.C:153:0:
YEqn.H:30:14: error: ‘H2’ was not declared in this scope
         ROP_[H2].field() = -(reaction->R(Y[H2])()).source();
              ^
In file included from AMRreactingLMFoam.C:54:0:
/home/zhu/OpenFOAM/OpenFOAM-2.4.0/src/finiteVolume/lnInclude/readTimeControls.H:38:8: warning: unused variable ‘maxDeltaT’ [-Wunused-variable]
 scalar maxDeltaT =

显示H2没有定义，请问各位前辈在求解器中如何表示H2？