[mat_brain]

Hello guys, i defined a variable k as a tensor, where ∇k∇T = 0, like this:

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  11
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    format      ascii;
    class       volTensorField;
    object      k;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [1 1 -3 -1 0 0 0];

internalField   nonuniform List<tensor> 
8
(
    tensor(7 0 0  0 7 0  0 0 7)
    tensor(3 0 0  0 3 0  0 0 3)
    tensor(3 0 0  0 3 0  0 0 3)
    tensor(7 0 0  0 7 0  0 0 7)
    tensor(3 0 0  0 3 0  0 0 3)
    tensor(7 0 0  0 7 0  0 0 7)
    tensor(7 0 0  0 7 0  0 0 7)
    tensor(3 0 0  0 3 0  0 0 3)
);

But it's giving me an error, what am i doing wrong?
The error:

--> FOAM FATAL IO ERROR:
Expected a '(' while reading VectorSpace<Form, Cmpt, Ncmpts>, found on line 22 the word 'tensor(7'

file: /home/.../k at line 22.

    From function Foam::Istream& Foam::Istream::readBegin(const char*)
    in file db/IOstreams/IOstreams/Istream.C at line 92.