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Table 4

Number of outer GMRES iterations to convergence (its), exploiting different initial guesses (IG) with no preconditioning (P).

Setting Ca I 4227 Sr II 4077 Mg II h&k

P IG its itsP its itsP its itsP
No Zero 53 45 248
No (i) 47 39 214
No (ii) 47 39 214
No (iii) 36 34 185
No (iv) 36 34 184
No (v) 31 31 40

Notes. The labels have the same meanings as in Table 2. Results are for the problems considered in Table 3.

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